Understand your email
SMTP diagnostics
Check connectivity, SMTP capabilities and the TLS certificate. Get a clear server configuration report.
Start a checkFree diagnostics
Start a check
Analysis starts automatically upon receipt. Each address accepts one message.
Actionable results
From checks to solutions
Each report includes a result, an explanation and a next step. If there is not enough evidence, we say so explicitly.
- 01
What was found
Verified facts with a separate status for unknown results.
- 02
Why it matters
Clear explanations without having to decipher error codes.
- 03
What to do next
Practical steps for domain owners and administrators.
Your archive
Check history
Reports are available for 24 hours. Switching accounts displays the current user’s history.
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Questions and answers
What to know
Does a good result guarantee inbox delivery?
No. Mail providers consider reputation, complaints and recipient behaviour. These checks identify technical issues but cannot predict each provider’s decision.
Which blocklists are checked?
SpamCop and DroneBL. DroneBL also covers compromised devices and network abuse. Unavailable sources are marked as not checked. Other lists are outside this result’s coverage.
Who can see the message and report?
The report is available to the check owner. The original message is deleted after analysis and the report after 24 hours. Attachments are not opened and HTML is not executed. Do not send confidential data.